In order to optimize your Art Storefronts site (in regards to things like Billboards or Photo Galleries) you may find that you need to compress your image files. This will help keep site speeds up and loading times down. To learn more about this process, please review the guide below.
If you're interested in using Photoshop to compress your images for use on the web, please Learn: How To Save For Web and Devices. After you've saved your image you can upload it or you can further compress it by using a Size Optimization Tool.